This invention relates to a method for determining the antimicrobial agent sensitivity of a nonparaffinophilic microorganism and an associated apparatus.
Treating infections very often involves educated guesses by medical personnel as to the nature of the microorganism involved and the correct antimicrobial agent and quantity thereof needed to effectively treat the microorganism present in the infected tissue. Often times, there is a need to treat a mixed flora of several microorganisms. Medical personnel are acutely interested in rapidly ascertaining which antimicrobial agents, and which dosages, are necessary in order to assure effective inhibition of the growth of all microorganisms present in the patient.
There is presently no effective, efficient and economical way for a physician to rapidly ascertain which antimicrobial agent, and which dosage is necessary in order to treat the patient. A physician simply does not have available to him or her the type of information regarding antimicrobial agent sensitivity that would make a more exact selection of an antimicrobial agent possible and, once an appropriate antimicrobial agent is selected, facilitate a more precise dosage for treatment. If this information was available, a physician could more effectively treat the infection. Furthermore, because some antimicrobial agents are expensive, the information could be used so that only that amount of antimicrobial agent needed could be used to treat the infection. Finally, and most importantly, as antimicrobial agents can have undesired side effects, the information can be used to find the most effective antimicrobial agent and dosage thereof, which will limit the undesired side effects.
As used herein, the term "nonparaffinophilic microorganism" means any microorganism sustained by a carbon source other than paraffin. Examples of such nonparaffinophilic microorganisms include, but are not limited to, the following: Mycobacterium tuberculosis; Mycobacterium paratuberculosis; Mycobacterium leprae; Staphylococcus; Streptococcus; E. Coli; Listeria; Brucellae; Humemophilus; Treponema; Pneumococcus; Clostridium; Cryptococcus; Coccidioides; and Histoplasma. Also, as used herein, the term "patient" refers to a member of the animal kingdom, including human beings, whose body specimen is being processed by the method and apparatus of the invention.
U.S. Pat. Nos. 5,153,119 and 5,316,918 disclose methods and apparatus for identifying and testing the antibiotic sensitivity of Mycobacterium avium-intracellulare ("MAI"), a paraffinophilic microorganism. The inventor named on those patents is Robert-A. Ollar, one of the co-inventors of the invention disclosed herein. This method involves providing a receptacle containing an aqueous solution and inoculating into the solution a specimen. After this, a paraffin coated slide is placed into the receptacle. The slide is then observed for the presence or absence of growth of MAI.
Despite the existence of Dr. Ollar's patents, there still remains a need for a method of testing the antimicrobial agent sensitivity of one or more nonparaffinophilic microorganisms in a way that maximizes the efficacy of the antimicrobial agent used to inhibit growth of the one or more nonparaffinophilic microorganisms that may be present in a patient.